Such low-pressure discharge lamps are produced by the company OSRAM, for example under the designations DULUX D/E, T/E, T/E IN. To be more precise, the abovementioned lamps are compact low-pressure discharge lamps having a discharge vessel comprising at least four straight, parallel tubes, which are arranged in a polygon and are connected by means of cross connections at or close to the end sections of the straight tubes to form a single continuous and gas-tight discharge path.
Depending on the length and the diameter of the discharge vessel and of the diameter of the cross connections of the discharge tubes, very high voltages are often required to start the low-pressure discharge lamp.
The patent specification U.S. Pat. No. 6,614,166 discloses a low-preassure discharge lamp in which a metallic helical spring which runs parallel to the straight tubes is arranged in the center of the cylindrical cavity formed by the straight tubes of the discharge vessel in order to reduce the starting voltage, and, at the same time, to allow the light, which is radiated inwards into the cavity formed by the straight tubes and the cross connections of the discharge vessel, to pass, only slightly impeded.
The U.S. Pat. No. specification 6,064,152 discloses the use of a hollow cylinder made from electrically conductive material in the form of a metal foil in the interior formed by the straight, parallel tubes of the discharge vessel, as a result of which the starting voltage can be considerably reduced.
The disadvantage of said prior art is that the helical spring from U.S. Pat. No 6,614,166 and the metallic cylinder from the U.S. patent can be seen from the outside and impede the luminous flux.
WO 01/87019 discloses a fluorescent lamp, in which a starting aid is connected, on the one hand, to the base and, on the other hand, is in contact, in the form of a spring, with a limb of the discharge vessel without an electrode.